Timer or current-interrupter.



C. F. KETTERING.

TIMER 0R CURRENT INTERRUPTER.

APPLlcATloN man Nov. 14. 1910.

M nur' CwAtTm/.

UNITED STATES PATENT OFFICE.

CHARLES F. KETTERING, OF DAYTON, OHIO, ASSIGNOR TO THE DAYTON ENGINEERING LABORATORIES CO., A CORPORATION 0F OHIO.

TIMER 0R.' CURRENT-INTERRUPTER.

Sp'ecication of Letters Patent.

Patented Dee. 7,1915.

To all whom t may concern Be it known that I, CHARLES F. KETTER- ING, a citizen of the United States, residing at Dayton, county of Montgomery, and State of Ohio, have invented certain new and useful Improvements in Timers or Current-Interrupters, of which the 'following is a full, clear, and exact description.

This invention relates to timers or cur- -rent interrupters, and has among its objects to provide improvements in the mechanical construction of the same and to make them more eiiicient for their purposes, more particularly as applied to use in ignition systems for internal combustion engines.

With these and incidental objects in view, the invention comprises certain novel forms of construction, a preferred form of embodiment of which is shown in the accompanying drawing and described hereinafter.

In said drawings, Figure 1 is a vertical section through the timer taken on the line 1-1 of Fig. 2 and looking in the direction of the arrows. Fig. 2 is a top plan view of the timer.l Figs. 3, 4, and 5 are detail views of parts of the make-and-break device. Fig. 6 is a diagrammatic view of the ignition circuit.

The present application is a division of my previously filed application Serial No. 564737 filed June 3, 1910, which application in part shows the devices embodied in the present application.

Referring to diagrammatic Fig. 6, the battery 20 supplies current to an induction coil represented diagrammatically as at C; this induction coil comprises the usual primary and secondary, in the secondary of which is the usual spark-gap for the ignition system. The primary of this coil is connected with a circuit breaking device shown diagrammatically as at B, the construction of which is preferably of the sort to cause a single sparking impulse for each contact making of the timer, which timer will be presently described. It will be understood that this diagrammatic Fig. 6 is an abbreviation of the diagrammatic circuit shown in my other application above referred to, and reference may be made to said application for a more detailed description of some of these parts, the present application relating more particularly to the improved form of timer construction. Referring still to Fig. 6, this ignition circuit is controlled by a timer cam 24 attached to the shaft 25, which is adapted to make-andbreak the circuit. Adjacent to the cam 24 1s an arm 30 made fast to a hub or block 31 p lvoted at 32. This hub also carries a rcsilient contact arm 33 on the outer end of which 1s a contact point 34 adapted to make contact with a stationary point contact 35. These parts will be described more in detail later, it being sufficient for the present to state that the cam 24 in rotating strikes the projection 36 on the arm 30 and closes the contact at the points 34 and 35. The hub 31 is grounded by the wire 40 and the battery is grounded by the wire 41.

Referring now to Figs. l to 5 inclusive, the mechanical construction of the timer or current make-and-break mechanism will be now described. Fig. 1' shows part of the distributer mechanism which is also shown and described in my co-pending application above referred to but which may be disregarded for the present purposes. This distributer is located ljust above the timer and is operated from the same shaft as the timer. The driving shaft 60, shown in dotted lines Fig. l, is suitably connected to the engine shaft and geared to the proper ratio of movements to operate the timer in proper cycle. This driving shaft y60 drives a surrounding sleeve 61 which sleeve for convenience may be called the di'stributer shaft since it carries at its upper end the timer cam 24 and also the distributing mechanism above referred to. A collar 62 loosely surrounds the sleeve 6l and is formed with an annular groove 63 into which groove project rollers 64 (see Fig. 1) carried by yoke arms 65. This yoke may be called the advance yoke since it is operated to advance or retard the spark as is customary in mechanisms of this sort. The said collar 62 has extending centrally through it a pin 66 (see Fig. 1) over which fits the slotted end 67 of the driving shaft 60. Said cross-pin 66 also extends through a spiral slot 68 formed in said sleeve 61. By this means, the rotation of the driving shaft 60 acts through the cross-pin 66 to rotate the collar 62 and the sleeve 6l, that is, thus rotating the distributer shaft carrying the timer cam 24. The change of timing is effected merely by ,changing the relative positions of the driving shaft 60 and the distributer sleeve 61, this being accomplished by rotating the advance yoke about its pivotal shaft 69 (by means of suitable hand lever and connections). The result of thus rocking the advance yoke 65 is to move the collar 62 up or down, thus moving the cross-pin 66 up or down and thereby bearing upon the Walls of the spiral slot 68 to rotate different positions relatively to thedrive shaft 60. This at the same time of course changes the relative position of the timer cam 24 and advances or retards the time of the make-and-break. The sleeve 61 carries suitable roller bearing 70 at top and bottom, and is formed with a supporting liange 71 at the top and is locked in position by a suitable locking nut 72 at the bottom.

The make-and-break device controlled `by the timer cam 24 will now be described, with more particular reference to Figs. 2, 3, 4, and 5'. These parts have been described in general With reference to Fig. 6. There is also associated with the arm 30, a stop-arm 80, the exact shape of which is shown in Fig. 5. One end of this arm is screwed to the casing of the instrument, and the middle portion is slotted as at 81 to surround the pivotal stud 32 of the hub or block 31, thus holding the stop-arm in rigid position. At the other end of this arm a lateral projection 82 extends in under the arm 30 soas to form a stop for the inner movement of said arm toward the cam24. A spring 83 attached at one end to the stop-arm 80 and at the other end to the arm 30, holds the hub 31 rotated to the position shown in Fig. 2 with the arm 30 resting against the stop projection 82. The resilient contact arm 33, carrying the contact point 34, as already described is carried rigidly on the pivotal hub 31. The outer end of the arm 3Q is bent at right angles and is slottedat 84 on both sides (see Figs. 2 and 4), thus forming a T- shaped end which engages the forked extremity of the resilient contact arm 33 Fig. 3). There is a slight amount of play between the arm 33 and this slotted portion 84 of the resilient arm 33, for the purpose presently explained, (see also Fig. 1).

In the operation of this make-and-break device, the rotating cam 24 strikes the nose 36 of the arm 30, and this arm is of sufcient rigidity t-o turn the hub 31 on its pivot 32 thereby bringing the resilient contact arm 30 into contact-making position. The resilient arm 33 however yields further to the camming movement of the cam 24, this further movement being permitted by the resilient construction of the arm 33 and the method of mounting it, relative to the arm 30 and the slot 84. This additional movement of the resilient arm 33 will, of course, cause additional pressure between the contact elements 34 and 35. When the resilient the sleeve 61 into contact projection 24 rides by the nose 36 and brings a recess in the cam opposite said nose, the spring 83 rotates the hub 31 back to normal position with the arm 30 against its stop projection 82, thus breaking the contact. And if there should be any tendency of the contact points to stick, the T- shaped end of the arm 30 will, in returning, strike and pull the contact arm 33 back into non-contact position, this also serving to give a quick and positive break.

This form of construction has various advantages among which may be instanced the minimizing of the chattering of the contact upon rapid operation. Any momentum of the arm 30 caused by the impact of the cam 24 is taken up resiliently with the lost motion provided by the slotV 84 and serves merely to give increase in pressure on the resilient contact arm 33, While the return of the arm 30 serves quickly to bring back the contact arm 33. The contact terminal 35 is connected to a terminal stud or knob 85 to which the wire may be attached for connecting said contact to the rest of the circuit as shown in Fig. 6.

It is to be understood that the construction herein shown and described is only a preferred form of embodiment of the invention and that the same may be embodied in other forms all coming within the spirit or scope of this invention. v

What is claimed is as follows v 1. In an ignition device the combination with an electric circuit having a make-andbreak contact device therein including a fixed contact and a coperating movable contact element; of a main operating member constructed for intermittent movement of the contact element; and an intervening member between the operating member and the resilient movable contact, positively operated by the former to move the latter into contact position but resiliently yielding to the further pressure of the operating member. v

2. In an ignition device the combination with an electric circuit having a make-andbreak contact device therein including a resilient contact arm, and a pivotal block rigidly carrying said contact arm; of a main operating cam constructed for intermittent operation of the resilient contact arm; and an intervening arm attached to the said pivotal block and extending between the operating cam and said contact arm, said intervening arm being operated by the cam to rotate the pivotal block and carry the contact Varm into contact position under the pressure of said intervening arm.

3. In an ignition device, the combination with an electric circuit having a make and break Contact device therein, including a resilient contact element having parallel ears extending from the free end thereof; of a lio main operating member; and an intervening member having a ianged end provided with cut away portions on each side thereof to receive the extended ears of the movable element, the extent of said cut away portion being greater than the thickness of said ears, whereby said intervening member will be operated by the operating member to initially move the resilient contact element into Contact position and also resiliently yield to the further pressure of the operating member.

4. In an ignition device, the combination with a circuit making and breaking device including a movable contact element having ears projecting from the free end thereof; of a member having a flanged free end provided with a pair of spaced shoulders, the ears of said movable contact element being positioned between said shoulders, whereby the opposite faces of said movable contact element will be engaged by the respective shoulders; and an operating member for intermittently moving the above named elements into contact making position.

5. In an ignition device, the combination with a circuit making and breaking device, including a movable contact element, having ears projecting from the free end thereof;

of a member having its free end provided with slots, adapted to receive the ears of said contact element.

6.In an ignition device, the combination with a circuit making and breaking device, including a movable contact element comprising a resilient plate; a supplemental.

plate having restraining engagement with saidcontact plate; a pivotal mounting for said contact and supplemental plate; a guard member engaging the supplemental plate and positively limiting the movement thereof and of the contact plate in one direction; and a spring, one end thereof connected with said guard plate and the, other end to the supplemental plate to normally maintain the contact plate out of contact making position.

In an ignition device, the combination with a circuit making and breaking device, including a movable contact element comprising a resilient plate; a supplemental plate having restraining engagement With said contact plate; a pivotal mounting for said contact and supplemental plate; a guard member engaging the supplemental plate and ositively limiting the movement thereof and3 of the contact plate in one direction; and a spring, one end thereof connected with said guard plate and the other end to the supplemental plate to normally maintain the contact plate out of contact making position; and means for initially engaging said supplemental plate to swing the contact plate on its pivot into contact making position and then Hex the supplemental plate to increase the pressure on the contact plate in its contact making position.

In testimony whereof I affix my signature in the presence of two subscribing Witnesses.

CHARLES F. KETTERING.

Witnesses:

J. B. HAYWARD, CHAS. D. BRoNsoN. 

